A short circuit is an abnormal low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages and potentially cause the electrical circuit to incurring damage, overheating, fire or explosion.
To prevent an electrical circuit from incurring damage, overheating, fire or explosion, U.S. Pat. No. 5,724,218 discloses a circuit configuration connected to a current source and a load, has a predefined current level and comprises a depletion MOSFET, an enhancement MOSFET, a resistor, a variable thermal resistor and a current sensor. The load has a load current. The enhancement MOSFET comprises a gate.
When a predefined current level for the load current is exceeded, the gate of the enhancement MOSFET discharges with a defined current that is predefined by the current source to limit the load current.
However, the discharge is too slow to protect the enhancement MOSFET from the load current that rises rapidly when a short circuit occurs that results in the enhancement MOSFET being subjected to a high current for an excessively long time period.
Accordingly, a new circuit is needed to protect a circuit from an output short circuit.